Device to dislodge off-bottom drill stems stuck in well bores



Nov. 5, 1963 J. s. MARSHALL 3,109,433

DEV-ICE T0 DISLODGE OFF-BOTTOM DRILL STEMS STUCK IN WELL BORES Filed July 25, 1960 2 Sheets-Sheet 1 F/G FIG. 2 l5 /2 Nov. 5, 1963 J 5. MARSHALL 3,109,488

DEVICE TO I DISLODGE OFF BOTTOM DRILL STEMS STUCK IN WELL BORES Filed July 25, 1960 2 Sheets-Sheet 2 FIG: 4

INVENTOR United States Patent 3,109,488 DEVEE T0 DISLGD-GE OFF-BOTTOM DRILL STEMS STUCK IN WELL BSRES Joe Eoule Marshall, 611 Eastland Ave., Ruston, 1.21., as-

signor of one-third to Johnny Howard Marshall and one-third to Joe Souls Marshall, Jr., all of Ruston, La.

Filed July 25, 1960, Ser. No. 45,237

1 Claim. (Cl. 166-67) or rock bit while in contact with the earths surface or subsurface. Usually this cutteror rock bit is followed into the earths surface or subsurface by a drill string made up of perhaps ten (10) (more or less) drill collars with slightly less outside diameter than the rock bit and length approximately thirty feet per stand; following, attached to the drill collars, are ordinary drill pipe which have somewhat smaller outside diameter and are approximately 30 feet long. These aforesaid described drill string members being of varying outside diameter range generally produce a pertinent problem called stuck drill stem. This means that the aforesaid described members while in the earths surface can not be engaged into further drilling activity nor can they be removed from the bore hole because of this lodged position. Stuck drill stems are generally more likely to occur during coming out of the hole operations (removing the rock bit, the drill collars, and the drill pipe from the bore hole). Coming out of the hole operation is a frequent and normal procedure because of the continual need to change worn bits.

During coming out of the hole operations somewhere between the bottom of the hole and the earths surface, the different size diameters of the rock bit, drill collars, and drill pipe causes a squeeze between the formations of the bore hole and the periphery of one of the aforesaid cylinder members, thus causing stuck drill stem members.

The above mentioned factor causing stuck drill stems is only one example of the many different factors that contribute to this problem. However, the elongating tool that will be described in the following pages will attempt to overcome most of the many problems that are characteristic of stuck drill stem members, especially the financial expense and time consuming delay.

An object of the present invention is to provide an improved means over the contemporary means of dislodging stuck drill stem members within bore holes. Another object is to save valuable rig time which is inevitably lost because of this problem.

In the following there is described and shown by accompanying drawings, one means, of the many means, by which this invention is employed.

In these drawings:

FIG. 1 is an embodiment of the disclosed invention and the surrounded paramount associated parts that are involved in mounting device and activating device.

FIG. 2 is a perspective view of the dislodging device segregated from the surrounded associated parts and in operative position.

FIG. 3 is a perspective view of the retrievable plug shown in operative closed position and acting in conjunction with cylinder arm.

FIG. 4 is a perspective view of the retrievable plug shown in retrieving position.

in the preceding figurative drawings a hydraulically actuated telescoping cylinder mechanism A is shown in operative position with retrievable plug B. Said retrievable plug B is dropped or pumped down in drill stem cavity 1 to the bottom of the drill stem 2 where said plug B anchors on bit support 3. The drill stem cavity 1 is then completely pumped full of drilling mud. The weight of this trapped mud plus an additional pressure on said mud acts to loosen said stuck drill stem.

This hydraulically actuated telescoping cylinder mechanism A is screwed by pin 5 into drill stem 2 at drill stem box 6. Having cylinder 7 telescoped within cylinder 8, lower ends of snubbing lines 9 are attached to substructure of rig or to blow-out preventer 10, upper ends of snubbing lines 11 are attached to snubbable means 12 at eyes 13 and slack removed in these lines until lines are in taut position. Snubbing means 12 having horizontal swivel at 14 and vertical careening movement from use of pivotal means 15.

To prevent pressure leakage at peripheral contacting point 16 where cylinder arm 8 telescopes in conjunction with cylinder 7, there is placed a peripheral stufiing box 17 filled with suitable packing means 18 and compressed around peripheral contacting point 16 by stuffing nut 19.

This improved dislodging device is now in pre-operative position. To activate same a fluid under pressure is forced through parted connection 253 and into cavities 2i and 22 thereby causing cylinder arm 8 to move to extended position relative to cylinder 7. Since cylinder 7 is in snubbed position cylinder arm 8 will follow law of least resistance and move lodged member of drill stem 2 downward and out of lodged position.

After drill stem 2 is freed, there is a need to prevent the dropping of drill stem 2 into the open hole below lodged position. To do so, the elevators (not shown) will be latched 6" to 8 below shoulders of box 6. In case of rapid or slow drop of drill stem 2 during dislodging thereof, the elevators will catch on collar 6 and hold drill string 2 in free position until it is decided what action will be taken to enlarge the key seat.

Generally, after freeing drill stem from lodged position, it is necessary to circulate a fluid through this drill stem and back through squeezed position in hopes of eroding this position to a larger inside diameter. To per form this circulation process there is a need to retrieve plug assembly B from its anchored position on bit support 3. In so doing the driller will lower an overshot on the end of a sand line (not shown) through drill stem cavity 2. Upon contact of overshot with ball 23 of plug insert 24 a latching means within overshot will lock around ball 23 and in turn be lifted out of drill stem with complete plug assembly B. To prevent swabbing action from occurring during withdrawal of plug assembly B and also to warrant an equilibrium of pressure below and above plug B, an indentation has been fabricated at 25 on plug insert 24; thus establishing a by-pass 26 for fluid trapped above plug assembly B in drill stern cavity 1.

Circulating and rotating drill stem 2 will respectively erode and wallow squeezed position (key seat) into a sizable opening capable of letting the drill stem pass through at drill stems largest outside diameter. This, with the knowledge of where to expect this squeezed position, and using contemporary methods to overcome this very common problem will enable drilling contractor to withdraw his drill stem from the bore hole on his next attempt.

What I claim is new and desire to secure by Letters Patent is:

An apparatus adapted to dislodge a stuck off-bottom drill stem from a key seat in a well bore, comprising: a plug adapted to be lowered and anchored within the drill stem adjacent the key seated area thereof, a telescoping cylinder mechanism including an upper cylinder closed at its upper end and a lower cylinder telescopically connected to the upper cylinder and fluidly communicating therewith, said lower cylinder being attachable to the upper end of the stuck drill stem, snubbing mechanism for securing the upper end of the upper cylinder against longitudinal movement relative to a stationary surface structure, fluid inlet means in the cylinder mechanism through which hydraulic liquid may be forced into the cylinder mechanism and attached drill stem to exert bydraulic pressure on the stuck drill stem to dislodge same. References Cited in the file of this patent UNITED STATES PATENTS 

